ED100-V-TAL100RS

[FLO]

I thought it an excellent piece and well worth posting.

As do I

Steve

[Caldwell 14]

Thanks chaps, my last review for a while anyway. My bad back is now much improved, the extension is a most welcome additon to my mount. I went the long way round to aquire my ED100 with a SW Newton in the middle for a short time after I sold comrade scope. I would have kept the TAL if it hadn't have been for the dodgy back and the decission to give a newt a go, ah well, all's well that ends well, I'm really very happy with my gear, for me its perfect.

[nightfisher]

Perhaps some of us should organise a meeting, planning what scopes we will bring along to compare and then have a 'runaround' session comparing notes at the end and coming up with a general consensus. we could have set parameters maybe too - perhaps a fixed magnification in all scopes, say 150x using whatever eyepiece gets as close to that as possible. this would be 1) very enjoyable 2) very educational and 3) really quite valuable for others looking to buy a scope as a first scope or to compliment what they have. if anyone is at PSP, I am hoping to be more organised this time and take my 16" f4 (of course) and my 6" f11 as well as a suitcase dob.

Shane, im well up for this, i can supply a couple of fracs and a mak, i really like the idea of a limit on magnification, might have to wait till PSP but worth doing

[Marki]

I'd be up for it - would need to see if any pitches left for PSP first though

[nightfisher]

I'd be up for it - would need to see if any pitches left for PSP first though

Get your self along to it, its a really good event, with a great crowd of people

[Moonshane]

good idea Jules. PSP it is then! you can visit as a day/night visitor and bring a scope so even if no pitches left (unlikely) then you can still attend. anyway, we are a bit off thread now - I'll put something on the PSP thread.

[Caldwell 14]

Ok I think I'll come as well, be a laugh

[Moonshane]

would be great to meet too! it's a great event and when it's clear the skies are good, not fantastic but very good.

[Caldwell 14]

when it's clear the skies are good, not fantastic but very good.

Manchester is way to near

[Moonshane]

true, but less than the 9 miles I live from Manchester

[Dodge]

Great report, and interesting to me as a 100RS owner. Thanks for posting.

[nicnac]

a very enjoyable read

[Markinaboat]

IMHO the ED100 is a fantasic scope and work every penny of the £390 I spent on it, but that is all I would spend on one. If I had bought one new I think I would be feeling a little disapointed. For £250 you buy a TAL 100RS, A better looking scope, a more robust scope a scope with a smoother focuser, the same views on 99% of targets...you also get far more CA on Venus and I expect Jupiter too. The CA on Mars and the Moon is so small its not worth talking about in a 100RS.

The CA cut in Venus is dramatic (It will be on Jupiter too!) but it is its lightness and suitabilty for use with my newly extended AZ4 that does it for me, rock solid. I had a straight choice £250 for a TAL 100RS (plus £20 for a dove tail) or pay and extra 140 quid for the ED glass and a flight case, no contest...........simples

Hi Caldwell,

Have been scouring the ads for a used 100ED DS PRO and of course getting various opinions on suitable mounts. I was leaning towards the Porta Mount II or Skytee until I came across your fantastic review. Needless to say,the pier must be life-changing (bad back, neck etc) but I have read (somewhere) reports of the AZ4's attachment mechanism/screw/bolt?? not being very strong. Have you made any mods or am I worrying about nothing here?

My last question is you mentioned that you wouldn't have paid the new price for the scope. May I ask why as I will of course not wait for ever and will have to cough up the current £625 (to include a free 0.85 f reducer)?

Thanks again!

Mark

[John]

Caldwell14 has not been active on the forum for over a year now Mark so you may not get a response.

I have an AZ-4 mount though and it does a pretty secure job of holding a number of different 100mm / 102mm refractors that I have used on it, despite having just the single clamping screw.

You can get ED100's for £250-£350 on the used market and they come up quite regularly in the UK Astro Buy & Sell website:

http://www.astrobuysell.com/uk/

I guess this might be why there were some reservations about paying the full new price for one. I got my used ED120 for less than the new price of an ED100 come to think of it.

[Markinaboat]

Hi John,

Lets hope he's ok!

This is so helpful to know (about the mount/screw) so I can out the mount question to bed!

Unfortunately, Ive been unable to find a used one having been looking for two months now (other than telescope outlet at 589 but w/o the f reducer which makes a new one worth the additional £76). I don't have access to SGL classifieds as I only have around 30 posts and need 50. So will probably buy new at the end if the month.

Thanks for your quick reply.

Mark

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[Caldwell14]

Hi

The AZ4 with an extension mount is just perfect for the ED100, very stable. I never felt any concern about the bolt with holds the dovetail in place, it really is very safe. I highly rate and recommend the AZ4 (The ED100 is pretty good too) In the end (and after several other designs of scope) I ended up with the bigger brother to this set up, an ED120 with a Moonlight. I sold the head of the AZ4 and added a GIRO III, for me at least I found my perfect outfit. 

[Markinaboat]

The scope came with the EQ goto otherwise would've gone for the AZ4.

Doesn't the 16" extension make the e/p too high when close to horizontal?

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[John]

I'm glad Caldwell14 is OK - nice to hear from him again   

The scope came with the EQ goto otherwise would've gone for the AZ4.

Doesn't the 16" extension make the e/p too high when close to horizontal?


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You can adjust the height of the tripod legs if the 16" pillar extension puts the eyepiece too high when viewing an object close to the horizon. It's not something I do much as I have trees / houses / light pollution around most of my horizons !

For viewing objects above around 45 degrees the extra eyepiece height gives the back a rest from bending so much, which makes it easier to concentrate on the object in the eyepiece I find 

[Caldwell14]

I'm glad Caldwell14 is OK - nice to hear from him again   

You can adjust the height of the tripod legs if the 16" pillar extension puts the eyepiece too high when viewing an object close to the horizon. It's not something I do much as I have trees / houses / light pollution around most of my horizons !

For viewing objects above around 45 degrees the extra eyepiece height gives the back a rest from bending so much, which makes it easier to concentrate on the object in the eyepiece I find 

Very true. One of the joys of owning a moonlight (other than its wonderful build quality) is its rotatable ability, add that to the extension pier and you're in    

Nice to speak to you again John too 

[Solo05]

I am also a fan of the 100RS even though when I got it one of the baffles had gone sideways halfway down the tube.

I just removed the front optics, straightened the baffle and put it back together.  Simples.

Just taken my first image of the moon with it.

[nightfisher]

nowt wrong with that, im very lucky i have the 100rs and the 125r, plain greedy

[Naemeth]

I am also a fan of the 100RS even though when I got it one of the baffles had gone sideways halfway down the tube.

I just removed the front optics, straightened the baffle and put it back together.  Simples.

Just taken my first image of the moon with it.

001_adj.jpg

I must say I'm impressed. I can't notice any CA at all.

[Qualia]

I must say I'm impressed. I can't notice any CA at all.

Ay, being an achromatic the Tal 100rs will 'suffer' from CA but with its quality glass, relatively small aperture and long focal length, such aberration is muted, if not necessarily silenced. Indeed, on the Moon CA is really quite tricky to discern.

[John]

When a 4" achromat gets to around F/10 the CA becomes pretty unobtrusive I found. Its there because it's a feature of the design just as coma is in a newtonian. I think you have to get to around F/16 for it to be more or less CA free at the 4" aperture and even more for larger apertures.

I had a Vixen 102mm F/9.8 followed by a TAL 100 R F/10 and found they performed very similarly. Full marks to the TAL though because, at that time, it cost quite a bit less than half the cost of the Vixen.

My 6" F/12 achromat shows about as much CA as a 4" F/10 does - that would have to be around F/18 to be more or less CA free - a 9 foot long tube !. Finding a mount for the F/12 has been hard enough ..... 

[Naemeth]

When a 4" achromat gets to around F/10 the CA becomes pretty unobtrusive I found. Its there because it's a feature of the design just as coma is in a newtonian. I think you have to get to around F/16 for it to be more or less CA free at the 4" aperture and even more for larger apertures.

I had a Vixen 102mm F/9.8 followed by a TAL 100 R F/10 and found they performed very similarly. Full marks to the TAL though because, at that time, it cost quite a bit less than half the cost of the Vixen.

My 6" F/12 achromat shows about as much CA as a 4" F/10 does - that would have to be around F/18 to be more or less CA free - a 9 foot long tube !. Finding a mount for the F/12 has been hard enough ..... 

For that reason, I highly doubt a 6" F/18 is even made, and if it is it would probably be a custom build. The tube would be around 2.7m long    .

Interesting stuff though John, thanks for posting